Update README.md

Author: TixiaoShan

README.md

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 # LeGO-LOAM
 
-This repository contains code for a lightweight and ground optimized lidar odometry and mapping (LeGO-LOAM) system for ROS compatible UGVs. The system takes in point cloud  from a Velodyne VLP-16 Lidar (palced horizontal) and optional IMU data as inputs. It outputs 6D pose estimation in real-time. A demonstration of the system can be found here -> https://www.youtube.com/watch?v=O3tz_ftHV48
+This repository contains code for a lightweight and ground optimized lidar odometry and mapping (LeGO-LOAM) system for ROS compatible UGVs. The system takes in point cloud  from a Velodyne VLP-16 Lidar (palced horizontally) and optional IMU data as inputs. It outputs 6D pose estimation in real-time. A demonstration of the system can be found here -> https://www.youtube.com/watch?v=O3tz_ftHV48
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+## Lidar-inertial Odometry
+
+An updated lidar-initial odometry package, [LIO-SAM](https://github.com/TixiaoShan/LIO-SAM), has been open-sourced and available for testing.
+
 ## Dependency
 
 - [ROS](http://wiki.ros.org/ROS/Installation) (tested with indigo, kinetic, and melodic)